Electric switch



July 22, 1930. a E, GETCHELL 1,771,214

ELECTRIC SWITCH Filed June 8, 192"! s Sheets-Sheet 1 INVENTOR 16 Benjamin L. talus-11,

July 22, 1930. s. E. GETCHELL ELECTRIC SWITCH Filed June 8. 19

3 Sheets-Sheet 2 July 22, 1930. a. E. cam-$1031.11

'uwcrnrc swrrcn Filed June 8. 1927 3 Sheets-Sheet 3 lNVEh JTO R Benjamin E. Getchel],

Patented July 22, 1930 UNITED STATES PATENT OFFICE I BENJAMIN E. GETCHELL, 0F PLAINVILLE, CONNECTICUT, ASSIGNOR TO THE TRUM- IBULL ELECTRIC MANUFACTURING COMPANY, OF PLAINVILLE, CONNECTICUT, A

CORPORATION OF CONNECTICUT ELECTRIC SWITCH Application filed June 8, 1927. Serial No. 197,369.

My invention relates primarily to what are frequently termed entrance switches of the safety type.

The improvements, however, are directed to the construction and. arrangement of the insulating support, the switch mechanism per se and its relation to the fuse protective device.

The principal object of my invention is to provide asimple, reliable switch in which the fuses are entirely disconnected from all the switch terminals when the switch is in the open position regardless of which terminals the line wires may be connected to.

Another object is to provide a switch construction in which the fuses are accessible only when the switch is in-the open position.

Another object is to provide a switch construction in which the fuses are positioned in a receptacle, the walls of which co-operate with an opening in the cover to permit access to the fuses but prevent access to any of the switch parts or terminals when the'main cover is closed.

Another object is to provide a double break switch having the contacts so arranged that arcing is reduced to the minimum.

Another object is to simultaneously break the circuit at four points.

Another object is to provide a construction of the above character in which either plug or cartridge type fuses may be employed.

Another object is to provide a switch of the character set forth, the parts of which may be readily assembled or disassembled for repair or replacement.

Another object is to provide a safety switch construction in which the switch proper may be readily inserted into a box in which the switch operating crank and handle have already been mounted.

The invention is applicable to both single and multiple unit switches. I have shown it as applied to a meter service switch for a three wire circuit, one branch having a neutral bus bar.

the stationar contacts is mounted an insulating bar slida le in the base and carrying contact members which extend through the bar and are adapted to connect the stationary switch contacts of the respective pairs when the switch is on. When the circuit is opened the switch bar slides in the base and the movable contact plugs are thus housed between solid walls of insulation and the switch bar insulation is interposed between the pairs of stationary contacts, so that any arotendmg to form will be immediately snuffed out.

Fig. 1 is a front view ofa switch mechanism embodying one form of my invention, the switch being in the open circuit or off position and the cover of the box being shown open.

Fig. 2 is a transverse sectional view of the box looking upwardly at the switch mechanism. Fig. 3 is a longitudinal sectional view showing one of the movable switch members in the open circuit position, the switch being shown Without the box.

Fig. 4 is a rear view of a part of the switch mechanism.

Fig. 5 is a fragmentary transverse sectional view showing the method of guiding the movable switch member.

Fig. 6 is a fragmentary transverse sectional view showing one pair of stationary switch 1clonttacts and the cooperating movable con- Fig. 7 is an exploded perspective view showing one set of switch and fuse socket element and terminals.

Fig. 8 is a perspective view showing one switch unit in the closed circuit position.

Fig. 9 is a perspective view of a cartridge type fuse clip and screw.

The base 10 of the switch mechanism per se is preferably formed of insulating material and adapted to be secured in any suitable manner in a box 11 having a cover 12. The base 10 has an extension 13 for the fuse elements adapted to be located in line with the opening 14 in the cover, which opening is adapted to be closed by a slide 15.

The operating crank 16 is hinged, or otherwise suitably supported in the box, and prov the base. one side of the base by a screw 19 which vided with an external operatin handle 17.

It will only be necessary to escribe one of the switch units as the right and left hand units are identical except that they are reversed with respect. to the opposite sides of Circuit terminal 18 is secured at also secures the foot of the stationary switch contact 20. The circuit terminal 18 may also be secured by an additional screw 19. The other circuit terminal 21 is similarly secured to the base by a screw 22 which also secures the foot of the stationary switch contact 23.

The fuse terminals, such as the screw shell 24 and the center contact 25 are used within the extension 13. The screw shell is held in place in any suitable manner, as for instance, by the usual plate 26, insulating washer 26 and a screw 27 which passes through the bottom of the extension 13 and screws into the outer end of the bracket 28. The rear foot of the bracket 28 is secured to the base beneath the foot of the contact 29 by the screw 30, the contact 29 being arranged opposite the contact 20. The center contact screw 25 passes through insulating washer 26, through the bottom of the extension 13 and screws into the front end of the bracket 31. The rear end of the bracket 31 is secured to the back of the base together with the foot of the contact 32 by means of the screw 33, the contact 32 being arranged opposite to contact 23.

The movable contacts 34 and 35 are in the form of In s bar 36. Pre ersiily they are loosely mounted in transverse passages 37 and 38. The edges of the contacts 20, 29, 23 and 32 are preferably bevelled or inclined as shown particularly in Figs. 7 and 8 and the ends of;

the contact plugs 34 and 35 are preferably bevelled or rounded so as to facilitate the movement of the contact plugs between the stationary contacts. The insulating bar 36 is ided in a slot 39 in the back of the in s ating base. The walls of this slot or groove constitute housings for the ends of the contact plugs 34 and 35 in the open circuit position. The insulating material of the bar 36 is adapted to be interposed between the stationary contacts in the open circuit position so that there is no possibility at any time of arcin between t e contacts. The rear edge of t. e sliding bar 36 is supported on the wall 40 of the base and on the cross bar 41 which is let into the back of the base and secured in position by screws 42 which may assist in holding the circuit terminal 21 in place.

The rear of the base 10 is recessed to allow for the movement of the operating crank 16 as shown in Fig. 3 the side walls of the recess forming stops for the crank in the on and oil positions and the rear edge of the switch bar 36 is provided with a slot 43 to receive carried by the insulating the crank 16 so that the bar 36 may be reciprocated b the oscillation of the crank 16 and handle 1 The construction is such that the entire switch mechanism proper may be constructed and assembled and then inserted into the box over the crank 16 and secured in place, for instance, by screws such as 44 and 45.

By this construction it will be seen that I have provided a rugged and reliable constructlon in which a single circuit may be broken in four places without danger of arcmg and without requiring quick break or snap action mechanism. 7

The pairs of relatively stationary contacts are preferably formed of resilient material sothat they press against the sides of the insulating switch bar to hold it in position as well as pressing strongly against the ends of the movable contact plugs when the switch is in the on or closed circuit position.

The cover of a switch box of this class is usually sealed or locked against access by any but authorized persons. The side walls of the fuse receptacle extension 13 extend close to the under side of the cover 12 and coin cide with the o ening 14 in the cover. The cover is provi ed with a shutter or slide 15 adapted to close the opening 14 in the cover and is so arranged, with respect to the operating crank 17, that the slide must be closed before the switch can be moved to the on position and can be opened to permit access to the fuses only when the operating crank and the switch are in the off position. Obviously, this arrangement prevents access to any of the switch parts except the fuse termmals and these are accessible only when the switch is off and the fuse terminals are detad or entirely disconnected from the circu1 The fuse receiving extension 13 is arranged to receive the fuse terminals of either the plug type or fuse clips which are adapted to receive fuses of the cartridge type.

If the plug type is to be used, the screw shell 24 is seated in a shallow circular recess 24 and the connections are made as previously described and as shown in Fig. 3. If cartridge fuse clips are to be used, the clips 47 are positioned as indicated in Fig. 1 and the connections to the cooperating members such as 28 and 31 are made by means of screws 48, 49. For this purpose the base is provided with holes for screws 27 or 48 and holes 50 to be used when clips are used. Obviously this interchangeable feature is of considerable advantage.

Although I have shown the switch as applied to a meter service switch, it will be understood that the invention is broadly applicable to other uses and I wish it understood that the claims are to be construed broadly except where a limited construction is required by the terms of the claims or by the state of the prior art.

I claim:

1. An electric switch including an insulating base having a transverse recess, appurtenant stationary and movable switch members mounted on said base' and a switch crank "operably connected with said movable switch members and movable in said transverse recess and adapted to stop against the side walls of said recess in each direction of its operating movement.

2. An electric switch construction including an insulating base having a transverse recess at the rear and a longitudinal groove intersecting said recess and open at its ends toward the front of the base, a pair of sta- 4 ber carried by each end of said bar and adapt- I bar.

ed to connect the aws of the respective pairs of contacts and an operating member movable in said recess and co-actin'g with said 3. An electric switch includin an insu-' lating base havin a groove the en s of which are open toward t e front of the base and the intermediate portion of which is open toward the rear of the base, four contact jaws secured to said base, two of said jaws being on one side of saidgroove and the other two jaws bein on the. opposite side of said groove, an insu ating bar slidable in said groove between the oppositely disposed jaws and insertable into said oove from the rear of said base, connectm members carried by said bar and ad. te to be interposed between the opposite y disposed jaws and a fuse receptacle in front of the central part of said groove having fuse terminals connected to two of said jaws and circuit terminals con-. nected to the other two of said jaws.

BENJALHN E. GETCHELL. 

